A new high magnification technique has been developed to improve visibility of mammographic detail. The technique utilizes a scanning electron microscope equipped with a high sensitivity, high resolution, solid-state backscatter electron detector. Magnification greater than a factor of 150 is easily achieved and there is no additional radiation dose or risk to the patient. There are three parts to this research proposal: a retrospective clinical study on 200 diagnosed breast cases; a clinical study involving current patients presenting for breast examinations, estimated at 200 cases over the course of this project; a physics study designed to quantitate results and improve techniques. The aim of this project is to critically examine the radiographic criteria used in making the distinction between benign/malignant breast calcifications seen on mammograms and to determine if new criteria are demonstrable. The purpose of the study is to improve mammographic diagnosis and minimize negative biopsies.